Actuation system for a door lock, where the door lock comprises a lock bolt driven by rotation of a lock pin that is functionally connected to the lock bolt. The actuation system comprises a cylindrical handle (5) with an outer diameter of between 6 and 9 cm. The system comprises a first pin receiver (8a) centred on the cylinder axis and a second pin receiver (8b) provided off centred between the cylinder axis and the cylindrical handle in order to be flexible with respect to post-mounting the actuating system on doors with already existing lock.